Magnetic fixture



J. H. BARRETT MAGNETIC FIXTURE Filed Dec. 9, 1945 INVENTOR. Jbl'in H. Barrel/T.

Patented Aug. 13, 1946 MAGNETIC FIXTURE John H. Barrett, Hudson,

La Pointe Machine Tool Company, Hudson, Mass, a corporation of Maine Application December 9, 1943, Serial No. 513,599

2 Claims.

This invention relates to a magnetic fixture by which work may be secured for machine operations.

It is the general object of my invention to provide a magnetic fixture so constructed that the work may be conveniently held at a selected angle relative to a supporting magnetic table or other structure.

A further object is to provide a magnetic fixture having an angularly adjustable work-holding element, together with means for adjusting said element, and means for securing the same in adjusted position. I also provide a construction such that the magnetic force which holds the work in the fixture also looks the fixed and movable parts of the fixture in selected angular relation.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawing, in which Fig. 1 is a side elevation of my improved fixture, with certain parts shown in section;

Fig. 2 is a front elevation thereof, looking in the direction of the arrow 2 in Fig. 1; and

Fig. 3 is a partial sectional view, taken along the line 33 in Fig. 1.

Referring to the drawing, my improved fixture comprises a base III and a work support I I. Each of these parts is formed of alternately disposed plates I4 and I5 of magnetic and non-magnetic material respectively. The magnetic plates in the base are aligned with the magnetic plates in the work support and the non-magnetic plates are similarly aligned, as clearly shown in Fig. 2. The plates I4 are preferably of wrought iron or soft steel, and the plates I5 may be of brass or bronze or other non-magnetic material.

The several plates I4 and I5 forming the base are permanently assembled by cross rods (Fig. 1), and the plates I4 and I5 forming the work support II may be similarly assembled by cross rods 2I. The rods 20 and 2| may be headed or riveted in the outer plates to firmly hold the parts together.

The work support II is preferably formed as a segment of a cylinder, with a portion cut away to provide work-engaging surfaces and 26, preferably disposed at 90 to each other. When the surface 25 is parallel to the bottom of the base III, the surface 25 is preferably aligned with the top surface 21 of the base.

The base I0 is provided with an upper concave Mass, assignor to The recess 30 to receive the cylindrical lower surface of the work support II. A retaining plate 40 iS secured to each end of the work support I I in any convenient manner, as by screws 4I. Each plate 40 is provided with a segmental rib 42 (Fig. 3) on its inner face, which rib is a sliding fit in a corresponding segmental groove 44 formed in the adjacent end face of the base III. The ribs 42 and grooves 44 thus hold the base III and work support II securely in assembled relation, while permitting angular movement of the work support.

An end portion of the cylindrical outer surface of the work support I I is preferably provided with gear teeth forming a segmental rack which is engaged by a pinion 5I rotatably mounted on a stud 52 fixed in the base II). The end face of the base is recessed as indicated at 53 to receive the pinion 5|, and the pinion is provided with a knurled head 55 by which it may be conveniently turned. This construction provides convenient means for angularly adjusting the work support I I on the base I0.

Each segmental plate 40 is provided with a segmental slot through which extends a stud GI fixed in the base I0. Wing nuts 62 on the studs 6I provide convenient means for clamping the base I0 and work support II in selected angular relation.

One end of the base I!) may be provided with the graduated scale indicated in Fig. 1, which is positioned to coact with an index arrow on the adjacent plate at. By reference to the graduations, the angular displacement of the work support II may be conveniently ascertained.

With this construction, a piece of work W may be placed on the work support II and may be quickly and easily adjusted with the support to any desired angular position. After the adjustment is made, application of magnetic force will cause the work W to be firmly retained on the work support I I, the work support I I to be firmly retained in the base I0, and the base III to be securely held on the working surface of a magnetic chuck or table.

It will be understood that my improved workholding fixture is intended primarily for use on a supporting magnetic surface, as it hasno provision for generating magnetic force in itself.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A work holding fixture comprising a base and a work support, each formed of a plurality of axially adjacent and axially alternated magnetic and non-magnetic plates, each plate having a work holding and angularly recessed edge portion and a segmental circular edge bearing portion and said plates being secured in a longitudinally extended assembled structure, said base and support having coacting concave and convex cylindrical surfaces, said support having end plates with segmental locking ribs and said base having segmental grooves to receive said ribs,

whereby said base and support are continuously maintained in assembled sliding relation, and additional means to secure said support to said base in any selected angular position.

2. A Work holding fixture comprising a base and a Work support, each formed of a plurality of axially adjacent and axially alternated magsupport to said base.

said base and support are continuously maintained in assembled sliding relation, said plates having segmental slots and said base having studs extending through said slots, and clamping nuts on said studs'efiective to clamp said plates and JOHN H. BARRETT. 

